Combination coal-fed water heater



Oct. 3, 1939. w. K. sTALl-:Y 2,174,901

COMBINATION COAL-FED WATER HEATER Filed July 22, 1938 3 Sheets-Sheet lINVENTOR TTOR Oct. 3, 1939. w. K. STALEY COMBINATION COAIrFED WATERHEATER :5 sheets-sheet 2 Filed July 22, 1938 .INVENTOR Y/f maar Oct. 3,'1939. w. K. STALEY COMBIATION COAL-FED WATER HEATER Filed July 22, 19383 Sheets-Sheet 5 INVENTCDF? z. mmf/ 6 762 5::

P .1 I n@ ATOR Promod oef. 3, 1939 i f 2,174,901

UNITED STATES PATENT OFFICE.,

COMBINATION COAL-FED WATER HEATER William K. Staley, Morton, Pa.,assignor to Anthracite Industries, Inc., New York, N. Y., a corporationof Delaware Application July 22, 1938, Serial No. 220,615

4 Claims. (Cl. 126-344) The present invention relates generally to theair. All of these in association with the unit to automatic stoking andburning of coal and more which the burner was applied were the factors lparticularly to a unitary apparatus for supplywhich led to success.

ing fuel to and maintaining combustion in a Some of the objects of thepresent invention burner or retort of smaller dimensions and ere toprovide e coal burner and mechanical r capacity than any heretoforedevised and which feed for use with a heater unit to 'suppllr hotfunctions in the open air instead of being coli- Welter for home 115e 01the like; t0 provide e Cool ned in a combustion chamber, burning unit ofthe automatic type which will In heating apparatus as heretofore in useit eiiiciently burn barley size coal; t provide an m has been possibleduring the past several years, improved mechanical feed for a coalburning lo to more orV less successfully burn coal in a reunit; t0provide en improved Control for a metort located in a furnace orenclosed Combustion chanical coal feed wherein the rate of feed bearschamber, such coal being supplied thereto autoa direct relation to thesize of fuel and the heatmatically by means of a stoker from a bin oring effect thereof; to provide o novel dual air hopper as the case maybe. Where the burner is supply for a stolzer wherein a mein air supply15 enclosed, as in the ordinary house heating boiler furnishes air forcombustion purposes and a or furnace, quite efficient operating resultshave supplemental air supply furnishes air t0 temper been obtainedprovided the correct grade of anthe heated products end Ineke itDOSSlble to efthracite, such as buckwheat or rice gmdet` is fectivelycontrol the temperature of the water delivered to the bin or hopper.Such automatic or other medium being heated; and to provide 20equipment, however, is applied to comparativelv other improvements eSWill .hereinafter appearairtight furnaces, all air supplied beingfurnished In the eeeolnpenying drawings, Figure 1 repby means ofmechanical draft, and is furtherresents a side elevation of one form ofthe inmore adapted for the use of anthracite 0f larger vention inassociation with a hot Water heatingr size than barley. In consequence awide field system; Figure 2 represents a. side elevation of 25 ofcommercial use has been forced to await the the burner and fuel feedmechanism; Figure 3 solution of the problem of open air use withrepresents an end elevation of Figure 2: Figure cheap fuel. This neldincludes water heaters 4 represents a detail in plan of the burner;Figfor domestic use and no one heretofore has been ure 5 represents asectional detail of one form of able to produce a coal stoking andburningr unit the thermostat; and Figure 6 represents a sec- 30 soassociated. and combined with the ordinary tion 0n line 5-5 of Figure 1.

gas f uel type of water heater (minus the gas Referring t0 the drawingsone form cf the burner) which is practical or commercial, It presentinvention consists of a coal burning unit j would seem a very simplething to pattern a l0 arranged t0 be mechanically supplied with smallburner yand its stoker after its well known fllei by a Stoker il from oSllDelDOSed hopper |2- 35 large counter-part so that the miniaturedevice Theun-it l0 iS Shown in combination with a Coil could be used forwater heaters, which are rela- Water heater i3 of the Well known gesheated tively small as compared to furnaces, boilers and type but fromWhich the ges burner has been like heating units, but this is not thecase. When removed. In the illustrated form of the inven- -f o suchreduction in size was tried, the result was tion the heater `llimaintains a supply of hot 4o failure. Thus the dwarf burner and Stokerrewater in a storage tank I4 which is connected fused to function withany grade of coal which by Circulating Pipes l5 and i5 With the coil IThad worked satisfactorily in the known types of. of the heater I3. Itshould be noted that the burners and stokers. This was surprising andburner unit Il) is not only located well below the baflling. Continuedexperiments finally gave a coil I1 but is exposed on all sides to theatmos- 45 clue to success in the use of barley size coal Dhere and henceoperates Under Very unusual which has long since been abandoned as aprecconditions. Furthermore since the casing of a tical fuel formechanically red domestic burndomestic Water heater is of relativelySmell diers. Its use however did not come from a mere arneter, thediameter of the burner unit I0 must substitution of one fuel foranother, but in conalso be restricted being therefore of the order ofjunction with a complete reorganization of the approximately seveninches. In effect it becomes coal feeding means including an ingeniousbala miniature coal burner which through an nancing of rate of feed,control of feed by water l genious association with an inlet ue I8 hastemperature. forced draft, and the mixing of the been made to operateunder the most adverse gaseous products with a. supplemental supply ofconditions for this type of equipment. As shown 55 the flue I8 is oftruncate shape and is located between the coaxially positioned heater I3and mingling fresh air with the burning products.v

top face of the base bowl 22.

the unit I2. The large diameter of the nue I8 is considerably largerthan the diameter of the unit I in order to form an annular passage 20about the rim of the 4unit I0 as a means for This te pering of theproducts `of combustion `has been' found to be one of the majorrequirements for efficient operation of the unit ID and heater I3 as aunitary combination.

Referring to the burner unit Il), a retort 2| in the form of a funnelshaped casting is provided having a circular flange which seats upon theThe parts thus assembled are held in place by cotter pins 23. This is asimple and convenient assembly which is made possible by like materialin the two castings whereby warping of one part with respect to theother is avoided. The funnel part of the retort 2l is provided with aplurality of circumferentially arranged rows of tuyres 24, those nearestthe outlet end of the funnel part being of somewhat smaller diameterthan the remaining rows.v This avoids undue loss of air near the surfaceof the burning fuel.

Vlhe -bowl 22 is provided with a fuel inlet 25 and an air inlet 26, theformer leading directly to the inlet end of the retort 2I, and thelatter discharging into a chamber 21 which'surrounds the inlet 26 andthe perforated funnel part of the retort 2I. A removable plate 28 in thebottom of the bowl 22 permits the cleaning out of any collection finesor sediment when necessary.

For supplying air under forced draft to the air inlet 26, an air supplypipe 30 leads from the inlet 26 to the discharge side of a fan housing3| which is located below the hopper I2 and adjacent a motor 32, thedrive shaft 33 of whichV i I drives the blower fan 34.

For supplying fuel to the inlet 25, a conduit 35 leads from the inlet 25to and communicates with the downwardly flared hopper bottom 36. Asuitably mounted feed screw 31 of slow feed pitch is arranged within theconduit 35, and its shaft :it projects from the closed end of theconduit 35 to receive a driven ratchet wheel 40. A spring pressed pawl4I is pivotally mounted to ride upon the ratchet wheel to therebyprevent lback lash.

In order to actuate the ratchet wheel 40 for vstep by step feed and toregulate the step quantity according to water temperature conditions, awork pawl 42 is pivotally mounted on the short I" arm of a rock lever 43in position to engage the r being a fixed point 48 and the lever 43 toreturn the lever 43 after a ratchet working stroke.

is means for varying the stroke of the lever in accordance with thetemperature of the water heated, a link chain 50 connects the lever i3with a rock arm 5I which is fixed to a rock shaft 5E. An operating arm53 is also fixed to the shaft 52 and is joined to one end of a suitableflexible cable or chain 54, the other end of which is attached to thelong arm of a control lever 55 which is pivoted in a bracket 56 attachedto the housing of an expansion type of thermostat 51. the thermostathousing to seat against an expansion member 58 for actuation thereby.The action of the thermostat can be varied by means of a weight 60adjustable on the long arm of the control lever 55, and arranged to beset in a selac-ted position by a clamping screw 6|.

Attention is directed to the fact that the motor 32 is of the type whichcan be stalled for an indefinite periodwithout burning of the motorwindings, for example a motor of the shaded pole type has been found togive satisfactory results. mechanical drive which is designed sucientlystrong to stall the motor in case of a jam to thus save the mechanicalparts from injury. Such jams may be caused by foreign matter, such asnails, screws, nuts and the like, or large size coal accidentallyentering the coal worm. By this construction it is unnecessary to useshear pins or similar devices to prevent injury when the feed becomesobstructed. Also it should be noted that the motor and gear boxconstitute a driving unit which can be replaced by simply removing thefour holding capscrews. Furthermore the coal worm, thrust bearing andratchet The short arm of the lever 55 enters Associated with this motorunit is the assembly form a complete driven assembly which has beendevised wherein barley size coal can be successfully and efficientlyused for heating water for domestic use. It should be noted that smallquantities of coal in process of combustion possess no bankingcharacteristics and therefore when once ignited must be kept replenishedas consumed, which necessitates a continuously operating feeding means.Such continuous feed, even though regulated for a minimum and maximumfeed, tends to overheat the water and in order to avoid too high watertemperature (while at the same time maintaining efficient operation) anovel supplemental air supply means has been created to temper the hotproducts from the burner according to operating conditions.

Having thus described my invention, I claim: l. A combination of a waterheater consisting of a water circulating coil'and a tubular casingenclosing said coil for the passage of products of combustion, saidcasing being arranged to discharge gases at its upper end and open tothe atmosphere at its lower end, a burner unit co-' axially locatedbelow said casing, means for feeding coal continuously to said unit, aforced draft to supply air only to said unit, means to vary the rateofcoal feed according to the water temperature, and an inlet for air atatmospheric pressure to said casing, said inlet being so associated withsaid casing and said unit that the quantity of supplemental airtraversing said inlet is controlled by the pressure of the gaseousproducts in said casing whereby under pilot conditions of said burnerunit the efficiency of heat transfer from the products of combustion isreduced.

2. The combination with an enclosed water heater having an open bottomto receive products of combustion to heat the water, of a continuouslyoperable coal burning unit to produce the products of combustion, meansfor feeding fuel to said unit at a varying rate in accordance with heatdemand of the water to be heated,.a forced draft mechanism to supply anon-variable volume of air to said unit, and means to vary the thermalemciency of the products of combustion in the heater to maintaincombustion in the burner unit under pilot conditions without overheatingthe water including a supplementary supply of air under atmosphericpressure fed directly into said heater at a point above and innon-eombustive relation to said unit.

3. A replacement burnerunit foia gas fired water heater consisting of acoal burning retort, means for feeding coal continuously to said retort,a forced draft to supply air to said retort, means responsive to thetemperature of the water being heated to vary the rate ot fuel feed, andmeans including a supplemental air supply delivered directly into saidheater at a point above and in non-combustive relation to said retort toprevent overheating of the water when said fuel feed is functioning ata. minimum rate.

4. The combination of a water heater and a coal burning unit, saidheater including a casing forming a combustion chamber open at thebottom and a water coil in said chamber, said unit being disposedcoaxially below said bottom, means forming an annular passage about saidunit to admit air to said chamber according to pressure conditions insaid chamber to vary the efficiency of heat transfer from the productsof combustion to the water in said coil, means for feeding fuel to saidunit, and a forced draft mechanism to supply air only to said unit tosupport combustion.

WJLLIAM K. STALEY.

